News /own research

Christina Flammensbeck, a master student at the LMU Munich is doing her IRT2 internship with us.She analyses inter- and intraspecific variation of tooth morphology in etmopterid (suprise!) sharks .Some of her first results are very exciting: analyzed male sharks show a higher number of lateral cusplets in upper teeth compared to females. Thanks for the images and your hard work Chrissi!

New images at shark-references:

Many thanks to the following persons for the permission to use their images:

HOLMGREN, N. 1940 Studies on the head in fishes. Embryological, morphological, and phylogenetical researches. Part I. Development of the skull in sharks and rays. Acta Zoologica (Stockholm), 21 (1-3): 51-267

HUMAN, B.A. 2011 Description of a unique catshark egg capsule (Chondrichthyes: Scyliorhinidae) from the North West Shelf, Western Australia. Aqua, International Journal of Ichyology, 17 (4): 199-209

Upcoming Meetings:

SIBIC 2016: VI Iberian Congress of ichthyology. 21.-24. June 2016, Murcia, Spain;a special session will be dedicated to Chondrichthyan research!

SIGNIFICANT DATES:

Registration starting on 1st September 2015

Call for abstracts starting on 1st October 2015

Abstracts submission deadline: 15th February 2016

Early-bird registration fee deadline: 31st March 2016

http://www.um.es/sibic6/en/presentation/

Annual joint meeting of Ichthyologists and herpetologists including the American Elasmobranch Society meeting. 2016: New Orleans, Louisiana, 6.-10. July 2016, New Orleans. Lousiana, USA. http://www.asih.org/meetings

Abstract: The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats.

Abstract: A species of Serendip Brooks and Barriga, 1995, Serendip danbrooksi n. sp., is described from Mexico as a parasite of Rhinoptera steindachneri Evermann and Jenkins, 1891. The new species differs from Serendipdeborahae, the type and only other known member of the genus, by having bothridia subdivided by 2 septa, 1 simple and 1 bifurcating, rather than 3 septa, 2 simple and 1 bifurcating, and by having 37–61 testes versus 64–116 testes, respectively. In general, S. danbrooksi n. sp. is smaller than S. deborahae in the number of proglottids (average 77 vs. 150, respectively) and length (maximum length 15.3 mm vs. 60.0 mm, respectively). Clarification of the details of some previously described structures is discussed.

New synonyms: Glyphissiamensis and Glyphisfowlerae are junior synonyms of Glyphisgangeticus

Abstract: For over a hundred years, the “river sharks” of the genus Glyphis were only known from the type specimens of species that had been collected in the 19th century. They were widely considered extinct until populations of Glyphis-like sharks were rediscovered in remote regions of Borneo and Northern Australia at the end of the 20th century. However, the genetic affinities between the newly discovered Glyphis-like populations and the poorly preserved, original museum-type specimens have never been established. Here, we present the first (to our knowledge) fully resolved, complete phylogeny of Glyphis that includes both archival-type specimens and modern material. We used a sensitive DNA hybridization capture method to obtain complete mitochondrial genomes from all of our samples and show that three of the five described river shark species are probably conspecific and widely distributed in Southeast Asia. Furthermore we show that there has been recent gene flow between locations that are separated by large oceanic expanses. Our data strongly suggest marine dispersal in these species, overturning the widely held notion that river sharks are restricted to freshwater. It seems that species in the genus Glyphis are euryhaline with an ecology similar to the bull shark, in which adult individuals live in the ocean while the young grow up in river habitats with reduced predation pressure. Finally, we discovered a previously unidentified species within the genus Glyphis that is deeply divergent from all other lineages, underscoring the current lack of knowledge about the biodiversity and ecology of these mysterious sharks.

Dermal denticles are tiny tooth-like scales that line the skin of nearly all elasmobranch species, providing a hard yet flexible armour that is gradually shed and regenerated. Their hydrodynamic design has provided inspiration for swimsuits worn by Olympic athletes, drag-eliminating coatings for vehicles, and even surfaces that impede bacterial growth in hospitals. But can they be used for shark conservation?http://saveourseas.com/update/shark-skin-sleuthing/